(1) Field of the Invention
This invention relates to a substrate treating apparatus for treating semiconductor wafers, glass substrates for liquid crystal displays and the like (hereinafter called simply “substrates”). More particularly, the invention relates to a substrate treating apparatus having a holding device for holding substrates in a cantilever mode.
(2) Description of the Related Art
Conventionally, this type of substrate treating apparatus has a treating tank for treating substrates, a holding mechanism for holding a plurality of substrates in upstanding posture by contacting lower edges thereof, and for placing the substrates in the treating tank, and a transport mechanism for holding the substrates at side edges thereof and transferring the substrates to and from the holding mechanism (see Japanese Unexamined Patent Publications Nos. 8-340035 (1996) and 11-289000 (1999), for example).
The transport mechanism holds and moves the substrates to be treated above the holding mechanism, the holding mechanism subsequently moves upward relative to the transport mechanism, and the transport mechanism releases the substrates to be received by the holding mechanism. Then, the holding mechanism lowers to the treating tank to place the substrates in the treating tank for treatment. After the treatment, the holding mechanism moves up, and the transport mechanism holds the substrates and transports the substrates to a next treating tank, for example.
The conventional apparatus having such a construction has the following drawback.
With the conventional apparatus, treated substrates sometimes have scratches made in the circumferential direction at edges thereof. Such scratches on the substrates lower their quality such as by producing crystal defects in the substrates, rendering the substrates susceptible to damage, or producing particles to cause mutual contamination.